Debate has focused on an outdated concept of health care. Photograph: Martin Godwin

Doctors and nurses will have to be made redundant in order to reshape the NHS and social care system to meet the changing needs of the ageing population, a leading Tory has said.

Stephen Dorrell, chair of the influential Commons health select committee, told social care leaders that the NHS needed a rethink to free resources to care for the fast-growing numbers of people living with long-term conditions such as diabetes, arthritis and depression.

"Does that mean redundancies for individual doctors and nurses? Well, in some circumstances it probably will," he said.

Dorrell, who was health secretary in John Major's Tory government, has in recent weeks become increasingly outspoken in arguing that the health and social care bill – which he has voted for – misses the central challenge facing the care system.

Debate "in SW1" – the London postal district for Westminster and Whitehall – was focused on a wholly outdated concept of health care in which "a normally healthy adult who walks into a GP practice, is referred for secondary care, is treated, and walks out cured", Dorrell said.

In reality, such episodes account for just 10% of NHS activity. The bulk of care is for the 15 million people living with at least one long-term condition, who need hospital treatment only rarely. The National Audit Office had found that 30% of non-emergency hospital admissions could be avoided with better services in the community.

"Just think about what we could do with the resources that would be freed if that 30% were avoided because we delivered more integrated, more effective, high-quality frontline community-based services," Dorrell said.

The health select committee is beginning an inquiry into social care that looks certain to call for urgent action on integration of health and social care, particularly through joint commissioning of services through single budgets.

Dorrell's comments were welcomed by Peter Hay, president of the Association of Directors of Adult Social Services. He said: "He set us a challenge, very bravely acknowledging the context of staffing when we address how to achieve this change locally."

Paul Burstow, care services minister, told the conference that the outlook for social care was likely to remain tough in funding terms for "the next few years".

Some local authorities were dealing with financial constraint better than others, Burstow said. "Good decisions by everyone? In some places, yes; in other places, hopeless short-termism is there to be seen."